PinkNews.co.uk has learnt that Labour’s decision to grant its backbenchers a free vote on equal marriage caused a major rift in the shadow cabinet with deputy leader Harriet Harman amongst those calling for the vote to be whipped.

Speaking to PinkNews.co.uk, a Labour source described last week’s meeting of the shadow cabinet as descending into a “massive row” and that two prominent MPs threatened to resign from Labour’s frontbench – if the party went ahead with a whipped vote.

One of the individuals, a Labour parliamentary veteran, held top cabinet positions in both Gordon Brown and Tony Blair’s governments, and both MPs are of deep religious faith.